ORDER BY SQL datefield question

I'm trying to display data by a date field (MM/DD/YYYY) in DESC ORDER from a msSQL database by using ASP. By just using the standard SQl statement: 'ORDER BY DateCompleted DESC' This only will place data in descending order of Month with out using the day and year to place them in order. I'm sure I just need to 'strip' the data for it properly display it in order but I haven't so far been successful.

I also wanted to know how to build a WHERE statement that would only show 'Events' that haven't transpired.

I appreciate any help.